Year	Number
2004-01-01	26.3382
2005-01-01	28.7017
2006-01-01	29.8267
2007-01-01	32.2286
2008-01-01	35.8772
2009-01-01	35.2995
2010-01-01	35.7686
2011-01-01	38.4475
2012-01-01	38.8618
2013-01-01	39.5073
2014-01-01	41.1317
2015-01-01	25.0989
2016-01-01	24.7946
2017-01-01	24.4904